Sorry but this is total bunk. Moving an object the size of a grain of rice with sound waves is not a tractor beam. And I can go on and on. If I want this sort of crap, I'll check my Facebook feed.
Worse, the level of technical description in sci-fi, even in 'hard' sci-fi, is terribly low. You really can't say a submarine 'powered by the sun' is the same as predicting electric subs and neither do you get credit for such things unless you really delve into the justifications for such a 'prediction' and explain a fair degree on how it would all work. Or that the communicators in star trek have anything to do with…
Re: Science fact: Sci-fi inventions that became reality
#31The best essay I've read on that is Ursula Le Guin's preface to Left Hand of Darkness: http://theliterarylink.com/leguinintro.html